Kale's hat can't be obtained even if you kill him so Santa might be a bit hard to pull off - although I suppose the Crimson Hood might be a decent alternative since it's at least red.

The Screamer is funny - bonus points if you are geared like a barbarian (fur raiment, great club, etc) and do it lol.

something involving the sleep torch

You should do 'The Great Slumberer' or something. Sword of St. Trina for the sleep mist, sleep pots, and the sleep torch. Make your opponent fall asleep then do the rest emote and lay down beside them.

I've yet to do this one because I haven't come across the weapon yet, but I kept invading this guy the other night with the name 'Jedi Knight' who was just wearing the Lazuli Sorcerer robe and dual wielding a Cipher blade (not the fist weapon Cipher Pata you get early on in the Roundtable Hold, but an actual sword version). He used lightning incantations, so it felt like I really was dueling Emperor Palpatine or some shit lol.

I've also come across a DBZ roleplayer named Goku who just spammed Comet Azur which was equally funny to me lol.